twisted_test.py 文件源码

def save_signal_handlers():
    saved = {}
    for sig in [signal.SIGINT, signal.SIGTERM, signal.SIGCHLD]:
        saved[sig] = signal.getsignal(sig)
    if "twisted" in repr(saved):
        if not issubclass(IOLoop.configured_class(), TwistedIOLoop):
            # when the global ioloop is twisted, we expect the signal
            # handlers to be installed.  Otherwise, it means we're not
            # cleaning up after twisted properly.
            raise Exception("twisted signal handlers already installed")
    return saved